1; Field of the Invention
This invention relates to a rail transport apparatus which transports objects by means of vehicles running on rails.
2. Description of Related Art
Reference ′435 (Japanese Patent Application Laid-Open under No. 2001-270435) discloses a rail transport apparatus which transports objects by way of transport vehicles supported by and suspended from the rails provided on the ceiling. Since such a suspension-type rail transport apparatus does not occupy the floor, it is useful for a clean room for semi-conductor manufacturing in which unit price for space is expensive.
Recently, in the semiconductor manufacturing factory, the scale of production is being remarkably enlarged and complicated. Therefore, the route of the rail provided in the above-mentioned transport apparatus becomes complicated and includes many branches and junctions.
However, in the transport apparatus disclosed in the Reference ′435, in an area in which one traveling rail is connected to another traveling rail via a connection rail, the connection rail becomes relatively long. As mentioned above, the unit price of the space is high in the clean room for the semiconductor manufacturing, and hence it is necessary to reduce the area occupied by the rail as much as possible. Therefore, there is a need to reduce the area occupied by the rail as much as possible and shorten the connection rail further.